25/12 isnt that hard, just start slowly and dont try to play it as fast as you hear on records. That is plenty of 'etude'
That's really not true. I know ppl who can play winterwind, and the 2nd, but still not play this very well. So it depends on your hand.Uhm.. Look through the preludes. Many of them are like the etudes, but shorter and not that difficult.
im not sure... i'd rather practice a piece in similar fashion and get the technique that way rather than butcher such a wonderful piece.